Field of the Invention
Embodiments of the present invention generally relate to field of display technique, in particular, to a substrate including a color filter layer made of electrochromic material, a liquid crystal display panel and a display device.
Description of the Related Art
A liquid crystal display panel mainly comprises an array substrate, a color filter substrate, and liquid crystal molecules disposed between the array substrate and the color filter substrate. Generally, the array substrate is provided with gate lines, data lines, thin film transistors (TFTs), and pixel electrodes thereon, and the color filter substrate is provided with a black matrix, a color filter layer and common electrodes thereon.
In an operation condition of the liquid crystal display panel, when a scanning signal with high level is input to a gate line, TFTs connected with the gate line are in an ON state, and a gray scale signal carried on the data lines is applied to the pixel electrodes through the TFTs, an electric field is formed between the pixel electrodes and the common electrodes to control liquid crystal molecules to rotate so as to modulate backlight which has transmitted therethrough, so that light having different spectrum wavelength band is irradiated onto the color filter layer of the color filter substrate, which color filter layer has different transmittances for the light having different spectrum wavelength band to present light with desired colors eventually.
When the liquid crystal display panel is required to display a low gray scale image, the electric field between the pixel electrode and the common electrode controls the liquid crystal molecules to rotate so as to modulate the transmittance of the backlight to achieve a low gray scale display. However, when the existing liquid crystal display panel performs the low gray scale display, a part of the backlight may transmit through the liquid crystal molecules to exit from the color filter substrate so that a light leakage may be generated in a dark state, resulting in a decreased contrast of the image displayed on the liquid crystal display panel, and thus affecting display quality of the liquid crystal display panel to some extent.